Optical network control planes provide automatic allocation of network resources in an end-to-end manner. Exemplary control planes may include Automatically Switched Optical Network (ASON) as defined in ITU-T G.8080/Y.1304, Architecture for the automatically switched optical network (ASON), the contents of which are herein incorporated by reference; Generalized Multi-Protocol Label Switching (GMPLS) Architecture as defined in IETF Request for Comments (RFC): 3945 and the like, the contents of which are herein incorporated by reference; Optical Signaling and Routing Protocol (OSRP) from Ciena Corporation which is an optical signaling and routing protocol similar to PNNI (Private Network-to-Network Interface) and MPLS; or any other type control plane for controlling network elements at one or more layers, and establishing connections there between. As described herein, these control planes deal with routing signals at Layers 0, 1, and 2, i.e., photonic signals, time division multiplexing (TDM) signals such as, for example, Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), Optical Transport Network (OTN), Ethernet, MPLS, and the like.
Conventionally, in a control plane-enabled network, when a failure interrupts a call path, the call is torn down and the head end redials the call. At the photonic layer (e.g., Dense Wave Division Multiplexing (DWDM)), gracefully adding and removing a call from the network takes time and the repair action is limited by photonic constraints (e.g., reach of an optical modem). In OTN, connections can be referred to as High Order (HO) where there is a single large client (i.e., an Optical channel Data Unit-k (ODUk) in an Optical channel Transport Unit-k (OTUk)) or Low Order (LO) where there is multiplexing (i.e., an ODUj into an ODUk).
As restoration speed is important, and removing unnecessary work is desirable. Conventionally, there are single link techniques that involve a single span between adjacent nodes such as described in commonly-assigned U.S. Pat. No. 7,391,720, “LOCAL SPAN MESH RESTORATION,” the contents of which are incorporated by reference herein. However, it would be desirable to have multi-span techniques or techniques based on attributes of the photonic domain or OTN domain, for local repair, which can improve restoration speed, avoid DWDM changes when necessary, and/or prevent HO/LO modifications in OTN.